Project Summary The ability to perform platelet separation with a high throughput, high recovery rate, high purity, and high platelet integrity is extremely important in many biomedical research studies and therapeutic applications (such as platelet transfusions). Centrifugation is currently the ?gold standard? laboratory technique used to obtain platelets from whole blood. However, this current approach for platelet separation often sacrifices the integrity of the platelets and disturbs them from their resting state. It has been reported that centrifugation processes significantly activate platelets, alter their morphology, reduce their membrane integrity, and affect platelet functions. These drawbacks limit the usefulness of the resulting platelet samples in many biomedical studies and clinical applications, resulting in many unmet needs. Our objective is to address these unmet needs by developing an acoustofluidic (i.e., the fusion of acoustics and fluid mechanics) based, platelet separation method that can maintain platelets in their resting state and preserve their properties and functions. When compared to conventional platelet separation techniques, our proposed acoustofluidic approach has already demonstrated a significantly lower level of activation, a higher platelet morphology score, and better membrane integrity. In Phase I of this SBIR project, we will demonstrate the feasibility and utility of this acoustofluidic platelet separation device. With unprecedented capabilities for maintaining platelet integrity, our acoustofluidic device will not only become a more compact and affordable replacement to the existing platelet separation approaches, but also fulfill many unmet needs in both fundamental biomedical research and therapeutics.